1. Field of the Invention
This invention relates to chrysoberyl gemstones and, more particularly, to chrysoberyl gemstones cut in a modified brilliant style.
2. Description of the Prior Art
The most important style of cutting diamonds and other colorless or faintly colored stones is the brilliant cut. This cut consists of 57 facets, a table and 32 facets in the crown and 24 facets in the base or pavilion of the stone. As the name suggests, this type of cut provides a brilliant gem, whose multiple reflections provide clean, sharp flashes of light, commonly called "fire" by gemologists.
U.S. Pat. No. 3,585,764, issued June 22, 1971 to J. Huisman et al., discloses a method of promoting brilliance in a diamond which includes thickening and polishing the girdle.
A variation of the brilliant cut is the Spectabril cut, which consists of 85 facets, a table and 3 rows of 12 facets each in the crown, 3 rows of 12 facets each in the pavilion and 12 girdle facets. The Spectabril cut was described by R. F. Thompson in Gems and Minerals, May, 1973, p. 39.
An attractive gemstone is chrysoberyl, BeAl.sub.2 O.sub.4 having the orthorhombic crystal structure. Many of these crystals exhibit pleochroism; that is, their color depends upon the viewing angle. Both natural and synthetic chrysoberyl have been cut in the brilliant style and variations thereof.